4 April 2013 - The fragility of South Africa’s electricity network was underlined when a fire at the Midas substation near Carletonville, west of Johannesburg, caused gold mines to shut down for several days in March 2013. About 400 MW of supply was affected by the fire. The mines which were affected included Sibanye Gold’s Driefontein mining complex. Sibanye is the entity which holds the majority of the former Gold Fields South African assets separated out from that group. Also affected were AngloGold’s Mponeng and Tau Tona mines.

Own generation projects such as a 2.0 MW methane powered electricity plant at the Beatrix gold mine, owned by Sibanye, and commissioned at the end of March 2013 will become more common as mines try to reduce their reliance on Eskom supplied power. Beatrix, located in the Free State, captures methane which being highly flammable presents an explosion risk at the mine’s underground workings.

Beatrix does having higher methane emission levels than other mines, and in time could produce 4.0 MW of electricity from this captured gas. The mine uses 82 MW of power, so while small the offset of electricity from the grid, will result in cost savings for the operation.

The mine plans to capture more of the gas it currently flares (1,600 litres a second) while 260 litres a second is sufficient for generating 2.0 MW.

To use methane like this must be a win-win situation. The cost of diverting the gas out of the mine, must be covered many times over by the revenue from the electricity generated.

Also, the methane released would previously have been going straight up into the atmosphere to become greenhouse gas causing climate change, and landfill gas is over 20 times more damaging in its warming effect than carbon dioxide, so there is a big gain for the planet from this use of this natural methane.